Add prism.js support

With new syntax highlighter prism.js, you have to configure which syntax highlighter you want to use between _highlight.js_ and _prism.js_. **However if you don't configure it, no syntax highligh will be apply** (where previously _highlight.js_ was forced by default).

Please upgrade you're `config.toml` (you can checkout `exampleSite/config.toml` to see sample) to re-add _highlight.js_ as syntax highlighter (except if you don't need it):

```toml
[params]
  syntaxHighlighter = "highligth.js"
```

fixes #24

1 files changed, 6 insertions, 0 deletions

diff --git a/src/scss/base/_custom.scss b/src/scss/base/_custom.scss
index 486f5e6..8d30383 100644
--- a/src/scss/base/_custom.scss
+++ b/src/scss/base/_custom.scss
@@ -5,4 +5,10 @@
         margin: 0 0.2em 0.25em -1.6em;
     	vertical-align: middle;
     }
+}
+
+pre.code-highlight > code {
+	padding: 0;
+	margin: 0;
+	line-height: inherit;
 }
\ No newline at end of file